Purpose: The aim of this study was to evaluate serum levels of leptin, ghrelin, and adiponectin in obese and non-obese children with asthma and in healthy non-asthmatic children, and analyze their relationships with clinical outcomes. Methods: This study enrolled 40 obese and 51 non-obese children with asthma and 20 healthy children. Body mass index and serum leptin, ghrelin, and adiponectin levels were determined in all children. Asthma symptom scores and lung function test results were recorded for subjects with asthma. Results: Serum leptin levels (11.8±7.9, 5.3±6.8, and 2.1±2.4 ng/mL in the obese asthmatic, non-obese asthmatic, and control groups, respectively) and adiponectin levels (12,586.2±3,724.1; 18,089.3±6,452.3; and 20,297.5±3,680.7 ng/mL, respectively) differed significantly among the groups (P<0.001 for all). Mean ghrelin levels were 196.1±96.8 and 311.9±352.8 pg/mL in the obese and non-obese asthmatic groups, respectively, and 348.8±146.4 pg/mL in the control group (P=0.001). The asthma symptom score was significantly higher in the obese children with asthma than in the non-obese children with asthma (P<0.001). Leptin and adiponectin levels were correlated with the asthma symptom score in non-obese children with asthma (r=0.34 and r=-0.62, respectively). Conclusions: Obesity leads to more severe asthma symptoms in children. Moreover, leptin, adiponectin, and ghrelin may play important roles in the inflammatory pathogenesis of asthma and obesity co-morbidity.